How Museums Deal With Clothes Moths

Clothes moths are not just ruining sweaters in closets. They are widely considered the number one insect pest in museums, especially for historic textiles and taxidermy. Webbing clothes moths, Tineola bisselliella, can chew through wool uniforms, feathered regalia, felt piano hammers and taxidermy mounts that are literally irreplaceable.

From the outside, it can feel mysterious. Museums are full of people and their jackets, with visitors constantly bringing in potential hitchhikers. Yet you rarely hear about catastrophic moth incidents, and when you do, there is usually a long writeup in a conservation journal rather than a viral TikTok.

So what do the professionals actually do?

The museum mindset – IPM instead of "spray and pray"

Almost every serious museum runs some form of Integrated Pest Management, or IPM. IPM is a strategy borrowed from agriculture and food storage. The idea is to focus on prevention, monitoring and targeted, low risk treatments, not routine blanket pesticide spraying.

Museum & heritage trial environments

An IPM program usually revolves around four repeating steps:

Prevention – design the building and routines so pests do not get in and do not find food or hiding places.
Monitoring – use traps and inspections to detect problems early.
Identification and diagnosis – confirm which pest is present and how bad the problem is.
Targeted treatment and follow up – use the least risky method that will work, document it, and then loop back to prevention.

Clothes moth control in museums is just IPM applied very seriously.

Museums don't rely on magic products. They use systematic prevention, early detection, and targeted treatments—strategies that work just as well in your home.

Step 1 – Keeping moths out in the first place

Museums cannot stop people coming through the doors, but they can do a lot to keep pests away from collections.

Building and housekeeping

Guidance from National Museums Scotland and others emphasizes simple things that sound boring and matter a lot:

Seal cracks and gaps where insects can crawl in
Keep doors and windows in good repair
Manage exterior lighting that attracts insects at night
Reduce clutter and dust in basements, attics and storage areas

Food is another big one. Most museums either ban food entirely from collection stores and galleries or confine it to specific cafe zones with strict cleaning schedules. Spilled crumbs are an invitation to all sorts of insects, not just moths.

Quarantine for incoming material

The riskiest thing in any collection is usually not the visitors. It is the material being added.

New acquisitions, returning loans, theatre costumes, taxidermy mounts and even packing crates can all arrive with live insects tucked away in seams and cavities. Best practice is to treat every incoming object as guilty until proven innocent.

Typical steps include:

Unpacking new or returning objects in a dedicated inspection area.
Checking them for frass, webbing and other signs of infestation.
Bagging anything suspicious in heavy plastic and sending it for low temperature treatment or anoxic treatment before it enters storage.

Some museums also quarantine things like incoming office furniture, exhibition props and packing materials, for exactly the same reason.

Visitors, coats and bags

What about all those wool coats coming through the door every winter?

Most museums separate their collections from visitor clothing in two ways:

Collection storage is not public. The really vulnerable textiles are normally kept in closed rooms, on compact shelving or in cabinets, with strict staff access. Visitors never bring coats into those spaces.
Galleries use distance and cases. Many textiles on display sit in sealed or glazed cases. Open display items, such as large tapestries, are usually roped off so visitors and their clothing cannot literally brush against them.

Cloakrooms are mostly there for comfort and security, but they also mean dripping coats and bags stay near the entrance instead of being carried deep into gallery spaces. Some institutions add discreet sticky traps in cloakrooms to monitor for moths and beetles coming in that way.

In other words, the system is designed so that a visitor jacket with moth eggs is a nuisance, not an immediate threat to a priceless textile.

Step 2 – Monitoring and early warning

Museums are full of traps.

A typical IPM program uses a mix of:

Blunder traps – small sticky traps on floors and in corners that catch whatever crawls or flies into them.
Pheromone traps – lures specific to clothes moths, carpet beetles or stored product moths placed in storage areas, cloakrooms and display cases.

Staff record what is caught where, usually on a quarterly or monthly schedule. Over time this builds a map of "normal" background activity and highlights hot spots that need extra attention.

Museumpests.net and similar resources provide photo rich fact sheets that help staff correctly identify what shows up on those traps, so they can distinguish webbing clothes moths from pantry moths or harmless house moths.

Step 3 – When a clothes moth shows up

Finding a male clothes moth on a pheromone trap in a cloakroom is not the same as discovering larvae chewing a historic cloak. The response depends on where and how many.

A very simplified version of what happens when things escalate:

Confirm the species and the area affected. Is it webbing clothes moth or case making clothes moth. Is activity limited to one textile store or scattered across several rooms.
Isolate the problem. Staff restrict access to the affected aisle or room, cover or wrap objects, and remove vulnerable items to a quarantine area where they can be treated.
Intensify monitoring and cleaning. Extra traps go in. Floors, baseboards, vents and shelving are vacuumed thoroughly, since dust and hair are moth food too.
Choose treatments for infested objects. This is where freezing and anoxia come in, which we will get to next.

The Peabody Museum case study

The Peabody Museum's "Moth Mitigation Project" is a textbook example. After discovering a webbing clothes moth outbreak in a large ethnographic textile store, they:

Surveyed the space and objects to map the extent of injury.
Created a multi year plan to clean, freeze and rehouse thousands of objects.
Improved storage materials and introduced ongoing IPM with traps and regular checks.

This is not spraying a can of insecticide and hoping for the best. It is closer to a long running project.

Step 4 – How they actually kill moths on objects

Museum treatment methods have to work on insects and be safe for materials that might be two hundred years old.

The three main tools are freezing, anoxic treatment and very targeted insecticide in the building fabric, not on the artifacts.

Freezing

Controlled low temperature treatment is now a standard, research backed method. Most museum pests, including clothes moths, are sensitive to sustained freezing.

Typical guidance looks like this:

For robust textiles and many mixed materials: at least 72 hours with the object core at around minus 30 °C, which in practice means 5 days at that setting.
For domestic freezers that reach minus 18 °C: two weeks or more to be safe.

Objects are wrapped in acid free tissue, sealed in plastic to manage condensation, then frozen and allowed to thaw slowly while still bagged.

It is simple, chemical free and works for a lot of museum textiles, though not for everything. Items under mechanical stress or with certain paints and finishes might need another approach.

Your household freezer is basically a tiny museum freezer if you bag items correctly and give them enough time.

Anoxic treatment

For sensitive objects that cannot be frozen, museums use oxygen free environments.

The idea is to seal the object in a barrier film bag or rigid chamber, then:

Flush with nitrogen or another inert gas, or
Add oxygen scavenger packets that slowly absorb the oxygen in the sealed space.

Insects cannot survive in oxygen below about one percent. Given a long enough exposure, all life stages are killed.

Anoxic systems are now available as commercial kits that heritage institutions can operate in house.

Limited insecticide use

Modern museum IPM guidelines strongly discourage blanket spraying of collections. Old school fumigants used to be routine and left behind arsenic and mercury residues that conservators now have to manage as hazardous.

Instead, museums may:

Use residual insecticide sprays such as products based on transfluthrin or permethrin in cracks, under baseboards and along thresholds, never directly on artifacts.
Apply insect growth regulators or surface treatments only on non collections building elements after consulting conservators.

For the objects themselves, freezing and anoxia remain the workhorses.

Step 5 – Rehousing and reducing future risk

After an infestation is brought under control, museums often treat it as an opportunity to upgrade storage.

Examples from recent projects include:

Moving textiles from open shelves into lidded, acid free boxes or garment bags.
Replacing old wool felt pads with inert foams or washed cotton.
Labelling and reorganizing shelves so staff can inspect objects without a lot of handling.

IPM is not a one time kill. It is a permanent change to the environment that makes moths less likely to thrive even if one slips in.

What you can borrow at home

You are probably not going to set up an anoxic fumigation chamber in the living room. But a lot of the museum playbook scales down nicely.

Think prevention first. Keep wool and silk clean, use sealed storage for long term, avoid keeping food in clothes storage areas.
Monitor rather than guess. Use a few well placed clothes moth pheromone traps and actually look at them.
Use freezing strategically. Your household freezer is basically a tiny museum freezer if you bag items correctly and give them enough time.
Only reach for insecticides when you understand exactly where and what you are treating.

Understanding how museums approach the problem also makes it easier to see why a single product like a cedar block or a single trap is never going to be magic on its own.

References

I read through museum IPM guides when I realized my apartment needed a system, not just products. The professional approach is surprisingly doable at home scale.

What I'd do instead

Use your freezer for small batches of wool items, sealed in bags, for at least two weeks
Set up a few pheromone traps in closets and check them monthly to catch problems early
Quarantine any new thrift finds or vintage textiles for a week before adding them to your closet
Clean and seal items before long term storage instead of relying on repellents alone

If you're deciding what to try next

— Notes from testing this in a small NYC apartment